
/*
 * Copyright 2011 Google Inc.
 *
 * Use of this source code is governed by a BSD-style license that can be
 * found in the LICENSE file.
 */
#include "SampleCode.h"
#include "SkView.h"
#include "SkCanvas.h"
#include "SkGradientShader.h"
#include "SkPath.h"
#include "SkRegion.h"
#include "SkShader.h"
#include "SkUtils.h"
#include "SkColorPriv.h"
#include "SkColorFilter.h"
#include "SkTypeface.h"
#include "SkAvoidXfermode.h"

static inline SkPMColor rgb2gray(SkPMColor c)
    {
    unsigned r = SkGetPackedR32(c);
    unsigned g = SkGetPackedG32(c);
    unsigned b = SkGetPackedB32(c);

    unsigned x = (r * 5 + g * 7 + b * 4) >> 4;

    return SkPackARGB32(0, x, x, x) | (c & (SK_A32_MASK << SK_A32_SHIFT));
    }

class SkGrayScaleColorFilter : public SkColorFilter
    {
    public:
        virtual void filterSpan(const SkPMColor src[], int count,
                                SkPMColor result[])
            {
            for (int i = 0; i < count; i++)
                {
                result[i] = rgb2gray(src[i]);
                }
            }
    };

class SkChannelMaskColorFilter : public SkColorFilter
    {
    public:
        SkChannelMaskColorFilter(U8CPU redMask, U8CPU greenMask, U8CPU blueMask)
            {
            fMask = SkPackARGB32(0xFF, redMask, greenMask, blueMask);
            }

        virtual void filterSpan(const SkPMColor src[], int count,
                                SkPMColor result[])
            {
            SkPMColor mask = fMask;
            for (int i = 0; i < count; i++)
                {
                result[i] = src[i] & mask;
                }
            }

    private:
        SkPMColor   fMask;
    };

///////////////////////////////////////////////////////////

#include "SkGradientShader.h"
#include "SkLayerRasterizer.h"
#include "SkBlurMaskFilter.h"

static void r0(SkLayerRasterizer* rast, SkPaint& p)
    {
    p.setMaskFilter(SkBlurMaskFilter::Create(SkIntToScalar(3),
                    SkBlurMaskFilter::kNormal_BlurStyle))->unref();
    rast->addLayer(p, SkIntToScalar(3), SkIntToScalar(3));

    p.setMaskFilter(NULL);
    p.setStyle(SkPaint::kStroke_Style);
    p.setStrokeWidth(SK_Scalar1);
    rast->addLayer(p);

    p.setAlpha(0x11);
    p.setStyle(SkPaint::kFill_Style);
    p.setXfermodeMode(SkXfermode::kSrc_Mode);
    rast->addLayer(p);
    }

static void r1(SkLayerRasterizer* rast, SkPaint& p)
    {
    rast->addLayer(p);

    p.setAlpha(0x40);
    p.setXfermodeMode(SkXfermode::kSrc_Mode);
    p.setStyle(SkPaint::kStroke_Style);
    p.setStrokeWidth(SK_Scalar1*2);
    rast->addLayer(p);
    }

static void r2(SkLayerRasterizer* rast, SkPaint& p)
    {
    p.setStyle(SkPaint::kStrokeAndFill_Style);
    p.setStrokeWidth(SK_Scalar1*4);
    rast->addLayer(p);

    p.setStyle(SkPaint::kStroke_Style);
    p.setStrokeWidth(SK_Scalar1*3/2);
    p.setXfermodeMode(SkXfermode::kClear_Mode);
    rast->addLayer(p);
    }

static void r3(SkLayerRasterizer* rast, SkPaint& p)
    {
    p.setStyle(SkPaint::kStroke_Style);
    p.setStrokeWidth(SK_Scalar1*3);
    rast->addLayer(p);

    p.setAlpha(0x20);
    p.setStyle(SkPaint::kFill_Style);
    p.setXfermodeMode(SkXfermode::kSrc_Mode);
    rast->addLayer(p);
    }

static void r4(SkLayerRasterizer* rast, SkPaint& p)
    {
    p.setAlpha(0x60);
    rast->addLayer(p, SkIntToScalar(3), SkIntToScalar(3));

    p.setAlpha(0xFF);
    p.setXfermodeMode(SkXfermode::kClear_Mode);
    rast->addLayer(p, SK_Scalar1*3/2, SK_Scalar1*3/2);

    p.setXfermode(NULL);
    rast->addLayer(p);
    }

#include "SkDiscretePathEffect.h"

static void r5(SkLayerRasterizer* rast, SkPaint& p)
    {
    rast->addLayer(p);

    p.setPathEffect(new SkDiscretePathEffect(SK_Scalar1*4, SK_Scalar1*3))->unref();
    p.setXfermodeMode(SkXfermode::kSrcOut_Mode);
    rast->addLayer(p);
    }

static void r6(SkLayerRasterizer* rast, SkPaint& p)
    {
    rast->addLayer(p);

    p.setAntiAlias(false);
    SkLayerRasterizer* rast2 = new SkLayerRasterizer;
    r5(rast2, p);
    p.setRasterizer(rast2)->unref();
    p.setXfermodeMode(SkXfermode::kClear_Mode);
    rast->addLayer(p);
    }

#include "Sk2DPathEffect.h"

static SkPathEffect* MakeDotEffect(SkScalar radius, const SkMatrix& matrix)
    {
    SkPath path;
    path.addCircle(0, 0, radius);
    return new SkPath2DPathEffect(matrix, path);
    }

static void r7(SkLayerRasterizer* rast, SkPaint& p)
    {
    SkMatrix    lattice;
    lattice.setScale(SK_Scalar1*6, SK_Scalar1*6, 0, 0);
    lattice.postSkew(SK_Scalar1/3, 0, 0, 0);
    p.setPathEffect(MakeDotEffect(SK_Scalar1*4, lattice))->unref();
    rast->addLayer(p);
    }

static void r8(SkLayerRasterizer* rast, SkPaint& p)
    {
    rast->addLayer(p);

    SkMatrix    lattice;
    lattice.setScale(SK_Scalar1*6, SK_Scalar1*6, 0, 0);
    lattice.postSkew(SK_Scalar1/3, 0, 0, 0);
    p.setPathEffect(MakeDotEffect(SK_Scalar1*2, lattice))->unref();
    p.setXfermodeMode(SkXfermode::kClear_Mode);
    rast->addLayer(p);

    p.setPathEffect(NULL);
    p.setXfermode(NULL);
    p.setStyle(SkPaint::kStroke_Style);
    p.setStrokeWidth(SK_Scalar1);
    rast->addLayer(p);
    }

class Line2DPathEffect : public Sk2DPathEffect
    {
    public:
        Line2DPathEffect(SkScalar width, const SkMatrix& matrix)
            : Sk2DPathEffect(matrix), fWidth(width) {}

        virtual bool filterPath(SkPath* dst, const SkPath& src, SkScalar* width)
            {
            if (this->INHERITED::filterPath(dst, src, width))
                {
                *width = fWidth;
                return true;
                }
            return false;
            }

        virtual Factory getFactory()
            {
            return CreateProc;
            }
        virtual void flatten(SkFlattenableWriteBuffer& buffer)
            {
            this->INHERITED::flatten(buffer);
            buffer.writeScalar(fWidth);
            }

    protected:
        virtual void nextSpan(int u, int v, int ucount, SkPath* dst)
            {
            if (ucount > 1)
                {
                SkPoint	src[2], dstP[2];

                src[0].set(SkIntToScalar(u) + SK_ScalarHalf,
                           SkIntToScalar(v) + SK_ScalarHalf);
                src[1].set(SkIntToScalar(u+ucount) + SK_ScalarHalf,
                           SkIntToScalar(v) + SK_ScalarHalf);
                this->getMatrix().mapPoints(dstP, src, 2);

                dst->moveTo(dstP[0]);
                dst->lineTo(dstP[1]);
                }
            }

        Line2DPathEffect(SkFlattenableReadBuffer& buffer) : Sk2DPathEffect(buffer)
            {
            fWidth = buffer.readScalar();
            }

    private:
        SkScalar fWidth;

        static SkFlattenable* CreateProc(SkFlattenableReadBuffer& buffer)
            {
            return new Line2DPathEffect(buffer);
            }

        typedef Sk2DPathEffect INHERITED;
    };

static void r9(SkLayerRasterizer* rast, SkPaint& p)
    {
    rast->addLayer(p);

    SkMatrix    lattice;
    lattice.setScale(SK_Scalar1, SK_Scalar1*6, 0, 0);
    lattice.postRotate(SkIntToScalar(30), 0, 0);
    p.setPathEffect(new Line2DPathEffect(SK_Scalar1*2, lattice))->unref();
    p.setXfermodeMode(SkXfermode::kClear_Mode);
    rast->addLayer(p);

    p.setPathEffect(NULL);
    p.setXfermode(NULL);
    p.setStyle(SkPaint::kStroke_Style);
    p.setStrokeWidth(SK_Scalar1);
    rast->addLayer(p);
    }

typedef void (*raster_proc)(SkLayerRasterizer*, SkPaint&);

static const raster_proc gRastProcs[] =
    {
    r0, r1, r2, r3, r4, r5, r6, r7, r8, r9
    };

static const struct
    {
    SkColor fMul, fAdd;
    } gLightingColors[] =
    {
        { 0x808080, 0x800000 }, // general case
        { 0x707070, 0x707070 }, // no-pin case
        { 0xFFFFFF, 0x800000 }, // just-add case
        { 0x808080, 0x000000 }, // just-mul case
        { 0xFFFFFF, 0x000000 }  // identity case
    };

#include "SkXfermode.h"

static unsigned color_dist16(uint16_t a, uint16_t b)
    {
    unsigned dr = SkAbs32(SkPacked16ToR32(a) - SkPacked16ToR32(b));
    unsigned dg = SkAbs32(SkPacked16ToG32(a) - SkPacked16ToG32(b));
    unsigned db = SkAbs32(SkPacked16ToB32(a) - SkPacked16ToB32(b));

    return SkMax32(dr, SkMax32(dg, db));
    }

static unsigned scale_dist(unsigned dist, unsigned scale)
    {
    dist >>= 6;
    dist = (dist << 2) | dist;
    dist = (dist << 4) | dist;
    return dist;

//    return SkAlphaMul(dist, scale);
    }

static void apply_shader(SkPaint* paint, int index)
    {
    raster_proc proc = gRastProcs[index];
    if (proc)
        {
        SkPaint p;
        SkLayerRasterizer*  rast = new SkLayerRasterizer;

        p.setAntiAlias(true);
        proc(rast, p);
        paint->setRasterizer(rast)->unref();
        }

#if 0
    SkScalar dir[] = { SK_Scalar1, SK_Scalar1, SK_Scalar1 };
    paint->setMaskFilter(SkBlurMaskFilter::CreateEmboss(dir, SK_Scalar1/4, SkIntToScalar(4), SkIntToScalar(3)))->unref();
#endif
    paint->setColor(SK_ColorBLUE);
    }

static int gRastIndex;

class TextEffectView : public SampleView
    {
        SkTypeface* fFace;
    public:
        TextEffectView()
            {
            fFace = SkTypeface::CreateFromFile("/Users/reed/Downloads/p052024l.pfb");
            }

        virtual ~TextEffectView()
            {
            SkSafeUnref(fFace);
            }

    protected:
        // overrides from SkEventSink
        virtual bool onQuery(SkEvent* evt)
            {
            if (SampleCode::TitleQ(*evt))
                {
                SampleCode::TitleR(evt, "Text Effects");
                return true;
                }
            return this->INHERITED::onQuery(evt);
            }

        virtual void onDrawContent(SkCanvas* canvas)
            {
            canvas->save();
//        canvas->scale(SK_Scalar1*2, SK_Scalar1*2, 0, 0);

            SkPaint     paint;

            paint.setAntiAlias(true);
            paint.setTextSize(SkIntToScalar(56));
            paint.setTypeface(SkTypeface::CreateFromName("sans-serif",
                              SkTypeface::kBold));

            SkScalar    x = SkIntToScalar(20);
            SkScalar    y = paint.getTextSize();

            SkString str("TextEffects");

            paint.setTypeface(fFace);

            for (size_t i = 0; i < SK_ARRAY_COUNT(gRastProcs); i++)
                {
                apply_shader(&paint, i);

                //  paint.setMaskFilter(NULL);
                //  paint.setColor(SK_ColorBLACK);

#if 1
                int index = i % SK_ARRAY_COUNT(gLightingColors);
                paint.setColorFilter(SkColorFilter::CreateLightingFilter(
                                         gLightingColors[index].fMul,
                                         gLightingColors[index].fAdd))->unref();
#endif

                canvas->drawText(str.c_str(), str.size(), x, y, paint);

                y += paint.getFontSpacing();
                }

            canvas->restore();
            }

        virtual SkView::Click* onFindClickHandler(SkScalar x, SkScalar y)
            {
            gRastIndex = (gRastIndex + 1) % SK_ARRAY_COUNT(gRastProcs);
            this->inval(NULL);

            return this->INHERITED::onFindClickHandler(x, y);
            }

        virtual bool onClick(Click* click)
            {
            return this->INHERITED::onClick(click);
            }

    private:
        typedef SampleView INHERITED;
    };

//////////////////////////////////////////////////////////////////////////////

static SkView* MyFactory()
    {
    return new TextEffectView;
    }
static SkViewRegister reg(MyFactory);

